Re: A super-efficient way to compute the sum of A[i] *

Hi Folks,

I need a super-efficient way to compute the sum of A[i] * B[i] for i=1 to

For example, suppose A is this:

<row>
     <col>0.9</col>
     <col>0.3</col>
</row>

and B is this:

<row>
     <col>0.2</col>
     <col>0.8</col>
</row>

I want to compute:

(0.9 * 0.2) + (0.3 * 0.8)

Here's one way to do it:

sum(for $i in 1 to count($A/col) return number($A/col[$i]) *

I suspect that is not the most efficient approach.

What is the most efficient approach? I will be doing hundreds of thousands

You can express it a bit more nicely in XPath 3 with higher-order
functions as